
#include "llvm-c/Disassembler.h"
#include "llvm-c/Target.h"
#include <stdio.h>

// #include "Disassembler.h"
#include "llvm/MC/MCAsmBackend.h"
#include "llvm/MC/MCAsmInfo.h"
#include "llvm/MC/MCCodeEmitter.h"
#include "llvm/MC/MCContext.h"
#include "llvm/MC/MCInstPrinter.h"
#include "llvm/MC/MCInstrInfo.h"
#include "llvm/MC/MCObjectFileInfo.h"
#include "llvm/MC/MCObjectWriter.h"
#include "llvm/MC/MCParser/AsmLexer.h"
#include "llvm/MC/MCParser/MCTargetAsmParser.h"
#include "llvm/MC/MCRegisterInfo.h"
#include "llvm/MC/MCStreamer.h"
#include "llvm/MC/MCSubtargetInfo.h"
// #include "llvm/MC/MCTargetOptionsCommandFlags.inc"
// #include "llvm/Support/CommandLine.h"
#include "llvm/Support/Compression.h"
#include "llvm/Support/FileUtilities.h"
#include "llvm/Support/FormattedStream.h"
#include "llvm/Support/Host.h"
#include "llvm/Support/InitLLVM.h"
#include "llvm/Support/MemoryBuffer.h"
#include "llvm/Support/SourceMgr.h"
#include "llvm/Support/TargetRegistry.h"
#include "llvm/Support/TargetSelect.h"
#include "llvm/Support/ToolOutputFile.h"
#include "llvm/Support/WithColor.h"

#include "llvm/AsmParser/Parser.h"

using namespace llvm;

static const Target* GetTarget(const char* ProgName)
{
    // Figure out the target triple.
    // if (TripleName.empty())
    //   TripleName = sys::getDefaultTargetTriple();
    Triple TheTriple(Triple::normalize("aarch64"));

    // Get the target specific parser.
    std::string Error;
    // const Target *TheTarget = TargetRegistry::lookupTarget("ArchName", TheTriple,
    //                                                        Error);
    const Target* TheTarget = TargetRegistry::lookupTarget("aarch64", TheTriple,
        Error);
    if (!TheTarget) {
        WithColor::error(errs(), ProgName) << Error;
        return nullptr;
    }

    // Update the triple name and return the found target.
    // TripleName = TheTriple.getTriple();
    return TheTarget;
}

static MCTargetOptions InitMCTargetOptionsFromFlags()
{
    MCTargetOptions Options;
    Options.MCRelaxAll = true;
    Options.MCIncrementalLinkerCompatible = true;
    // Options.DwarfVersion = DwarfVersion;
    Options.ShowMCInst = true;
    // Options.ABIName = ABIName;
    Options.MCFatalWarnings = true;
    Options.MCNoWarn = false;
    Options.MCNoDeprecatedWarn = false;
    return Options;
}

// static int fillCommandLineSymbols(MCAsmParser& Parser)
// {
//     for (auto& I : DefineSymbol) {
//         auto Pair = StringRef(I).split('=');
//         auto Sym = Pair.first;
//         auto Val = Pair.second;

//         if (Sym.empty() || Val.empty()) {
//             WithColor::error() << "defsym must be of the form: sym=value: " << I
//                                << "\n";
//             return 1;
//         }
//         int64_t Value;
//         if (Val.getAsInteger(0, Value)) {
//             WithColor::error() << "value is not an integer: " << Val << "\n";
//             return 1;
//         }
//         Parser.getContext().setSymbolValue(Parser.getStreamer(), Sym, Value);
//     }
//     return 0;
// }

static int AssembleInput(const char* ProgName, const Target* TheTarget,
    SourceMgr& SrcMgr, MCContext& Ctx, MCStreamer& Str,
    MCAsmInfo& MAI, MCSubtargetInfo& STI,
    MCInstrInfo& MCII, MCTargetOptions const& MCOptions)
{
    std::unique_ptr<MCAsmParser> Parser(
        createMCAsmParser(SrcMgr, Ctx, Str, MAI));
    std::unique_ptr<MCTargetAsmParser> TAP(
        TheTarget->createMCAsmParser(STI, *Parser, MCII, MCOptions));

    if (!TAP) {
        WithColor::error(errs(), ProgName)
            << "this target does not support assembly parsing.\n";
        return 1;
    }

    // // 这个可能有点危险,应该需要
    // int SymbolResult = fillCommandLineSymbols(*Parser);
    // if (SymbolResult)
    //     return SymbolResult;

    bool ShowInstOperands = true;
    bool LexMasmIntegers = false;
    bool NoInitialTextSection = false;

    Parser->setShowParsedOperands(ShowInstOperands);
    Parser->setTargetParser(*TAP);
    Parser->getLexer().setLexMasmIntegers(LexMasmIntegers);

    int Res = Parser->Run(NoInitialTextSection);

    return Res;
}

static std::unique_ptr<ToolOutputFile> GetOutputStream(StringRef Path,
    sys::fs::OpenFlags Flags)
{
    std::error_code EC;
    auto Out = std::make_unique<ToolOutputFile>(Path, EC, Flags);
    if (EC) {
        WithColor::error() << EC.message() << '\n';
        return nullptr;
    }

    return Out;
}

int main(int argc, char const* argv[])
{
    std::string TripleName("aarch64");

    // Initialize targets and assembly printers/parsers.
    llvm::InitializeAllTargetInfos();
    llvm::InitializeAllTargetMCs();
    llvm::InitializeAllAsmParsers();
    // llvm::InitializeAllDisassemblers();
    const char* ProgName = argv[0];
    const Target* TheTarget = GetTarget(ProgName);
    std::unique_ptr<MCInstrInfo> MCII(TheTarget->createMCInstrInfo());
    const MCTargetOptions MCOptions = InitMCTargetOptionsFromFlags();

    // std::unique_ptr<MCSubtargetInfo> STI(
    //     TheTarget->createMCSubtargetInfo(TripleName, MCPU, FeaturesStr));

    std::unique_ptr<MCSubtargetInfo> STI(
        TheTarget->createMCSubtargetInfo("aarch64", "", ""));
    std::unique_ptr<MCRegisterInfo> MRI(TheTarget->createMCRegInfo(TripleName));

    std::unique_ptr<MCAsmInfo> MAI(
        TheTarget->createMCAsmInfo(*MRI, TripleName, MCOptions));
    StringRef InputFilename("-");
    ErrorOr<std::unique_ptr<MemoryBuffer>> BufferPtr = MemoryBuffer::getFileOrSTDIN(InputFilename);
    if (std::error_code EC = BufferPtr.getError()) {
        WithColor::error(errs(), ProgName)
            << InputFilename << ": " << EC.message() << '\n';
        return 1;
    }
    MemoryBuffer* Buffer = BufferPtr->get();

    SourceMgr SrcMgr;

    // Tell SrcMgr about this buffer, which is what the parser will pick up.
    SrcMgr.AddNewSourceBuffer(std::move(*BufferPtr), SMLoc());

    // Record the location of the include directories so that the lexer can find
    // it later.
    // SrcMgr.setIncludeDirs(IncludeDirs);

    // FIXME: This is not pretty. MCContext has a ptr to MCObjectFileInfo and
    // MCObjectFileInfo needs a MCContext reference in order to initialize itself.
    MCObjectFileInfo MOFI;
    MCContext Ctx(MAI.get(), MRI.get(), &MOFI, &SrcMgr, &MCOptions);

    MCCodeEmitter* CE = TheTarget->createMCCodeEmitter(*MCII, *MRI, Ctx);
    MCAsmBackend* MAB = TheTarget->createMCAsmBackend(*STI, *MRI, MCOptions);

    // sys::fs::OpenFlags Flags = (FileType == OFT_AssemblyFile) ? sys::fs::OF_Text
    //                                                           : sys::fs::OF_None;
    sys::fs::OpenFlags Flags = sys::fs::OF_None;
    StringRef OutputFilename("test.o");
    std::unique_ptr<ToolOutputFile> Out = GetOutputStream(OutputFilename, Flags);

    std::unique_ptr<ToolOutputFile> DwoOut;
    // if (!SplitDwarfFile.empty()) {
    //     if (FileType != OFT_ObjectFile) {
    //         WithColor::error() << "dwo output only supported with object files\n";
    //         return 1;
    //     }
    //     DwoOut = GetOutputStream(SplitDwarfFile, sys::fs::OF_None);
    //     if (!DwoOut)
    //         return 1;
    // }

    std::unique_ptr<buffer_ostream> BOS;
    raw_pwrite_stream* OS = &Out->os();
    std::unique_ptr<MCStreamer> Str;

    Triple TheTriple(TripleName);

    if (!Out)
        return 1;

    {
        // assert(FileType == OFT_ObjectFile && "Invalid file type!");

        // Don't waste memory on names of temp labels.
        Ctx.setUseNamesOnTempLabels(false);

        if (!Out->os().supportsSeeking()) {
            BOS = std::make_unique<buffer_ostream>(Out->os());
            OS = BOS.get();
        }

        MCCodeEmitter* CE = TheTarget->createMCCodeEmitter(*MCII, *MRI, Ctx);
        MCAsmBackend* MAB = TheTarget->createMCAsmBackend(*STI, *MRI, MCOptions);
        Str.reset(TheTarget->createMCObjectStreamer(
            TheTriple, Ctx, std::unique_ptr<MCAsmBackend>(MAB),
            DwoOut ? MAB->createDwoObjectWriter(*OS, DwoOut->os())
                   : MAB->createObjectWriter(*OS),
            std::unique_ptr<MCCodeEmitter>(CE), *STI, MCOptions.MCRelaxAll,
            MCOptions.MCIncrementalLinkerCompatible,
            /*DWARFMustBeAtTheEnd*/ false));
        // if (NoExecStack)
        // Str->InitSections(true);
    }

    // Use Assembler information for parsing.
    Str->setUseAssemblerInfoForParsing(true);

    int Res = 1;
    Res = AssembleInput(ProgName, TheTarget, SrcMgr, Ctx, *Str, *MAI, *STI,
        *MCII, MCOptions);

    //
    // LLVMContext Ctx_llvm;
    // StringRef Source = "; Empty module \n";
    // SMDiagnostic Error;
    // auto Mod = parseAssemblyString(Source, Error, Ctx_llvm);

    return 0;
}
